GRAND RAPIDS, MI -- A day after the Boston Marathon explosions, local authorities say it's too early to say whether different security measures will be needed at this year's Fifth Third River Bank Run.

Mayor George Heartwell is certain, however, that the safety of runners and onlookers will be a key discussion among police and race organizers.

"I just want to be certain we do everything we can to make the event safe for everyone who participates," he said Tuesday, April 16.

The River Bank Run, billed as the largest 25K race in the country, attracts about 22,000 runners and is scheduled for May 11.

Heartwell said conversations are underway with Grand Rapids Police Chief Kevin Belk and River Bank Run organizers to look at security, in the aftermath of the Boston attack that killed three and injured 170.

Belk is expected to give a presentation about police-related River Bank Run issues to the City Commission on April 30.

In the meantime, police say the circumstances surrounding the Boston explosions may help dictate what changes, if any, are needed in Grand Rapids. A key piece of the puzzle is the group or individual behind the attack.

"We're trying to get a full picture of what we're dealing with here," said Grand Rapids Police Lt. Pat Dean, head of the department's special services unit. "Right now we're just trying to take a deep breath, step back and monitor the situation."

Dean said he does expect that River Bank Run organizers will encourage runners and onlookers to avoid leaving backpacks, duffel bags and other bags along the route.

Dean said that sometimes, runners who arrive at the last minute for the race will simply throw their bag under a bush or tree. That can be a security concern, he said.

The River Bank Run is the largest event that Grand Rapids Police staff and monitor, and about 100 Grand Rapids officers are assigned to different duties. Officers with Walker, Grandville and the Michigan State Police also help.

Typically, one of the biggest concerns is traffic control, he said.

In the past, security has not been on the front burner, Dean conceded.

Dean said he did not want to speculate on what security changes might be appropriate for the River Bank Run. He does anticipate more of a police presence.

"We'll probably add some staff," he said. "But we don't want to make any decisions based on misinformation or no information."

Heartwell said it's also possible that local authorities will work with the Federal Bureau of Investigation and the Alcohol, Tobacco, Firearms and Explosives division to make sure safety is optimized.